The Super-Kamiokande detector has measured solar neutrinos for more than 25 years. The sensitivity for solar neutrino measurement is limited by the uncertainties of energy scale and background modeling. Decays of unstable isotopes with relatively long half-lives through nuclear muon capture, such as 16N, 15C, 12B, and 13B, are detected as background events for solar neutrino observations. In this study, we developed a method to form a pair of stopping muon and decay candidate events and evaluated the production rates of such unstable isotopes. We then measured their branching ratios considering both their production rates and the estimated number of nuclear muon capture processes as Br(16N) = (9.0 ± 0.1)%, Br(15C) = (0.6 ± 0.1)%, Br(12B) = (0.98 ± 0.18)%, Br(13B) = (0.14 ± 0.12)%, respectively. The result for 16N has world-leading precision at present and the results for 15C, 12B, and 13B are the first branching ratio measurements for those isotopes.
Measurement of the branching ratio of 16N, 15C, 12B, and 13B isotopes through the nuclear muon capture reaction in the Super-Kamiokande detector / Maekawa, Y.; Abe, K.; Abe, S.; Asaoka, Y.; Harada, M.; Hayato, Y.; Hiraide, K.; Hosokawa, K.; Ieki, K.; Ikeda, M.; Kameda, J.; Kanemura, Y.; Kataoka, Y.; Miki, S.; Mine, S.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakayama, S.; Noguchi, Y.; Pronost, G.; Sato, K.; Sekiya, H.; Shimizu, K.; Shinoda, R.; Shiozawa, M.; Suzuki, Y.; Takeda, A.; Takemoto, Y.; Tanaka, H.; Yano, T.; Itow, Y.; Kajita, T.; Nishijima, R.; Okumura, K.; Tashiro, T.; Tomiya, T.; Wang, X.; Fernandez, P.; Labarga, L.; Samudio, D.; Zaldivar, B.; Yanagisawa, C.; Kearns, E.; Mirabito, J.; Wan, L.; Wester, T.; Pointon, B. W.; Bian, J.; Cortez, B.; Griskevich, N. J.; Jiang, Y.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Yankelevich, A.; Hill, J.; Jang, M. C.; Lee, S. H.; Moon, D. H.; Park, R. G.; Yang, B. S.; Bodur, B.; Scholberg, K.; Walter, C. W.; Beauchêne, A.; Drapier, O.; Ershova, A.; Mueller, Th. A.; Santos, A. D.; Paganini, P.; Quach, C.; Rogly, R.; Nakamura, T.; Jang, J. S.; Litchfield, R. P.; Machado, L. N.; Soler, F. J. P.; Learned, J. G.; Choi, K.; Iovine, N.; Cao, S.; Anthony, L. H. V.; Martin, D.; Prouse, N. W.; Scott, M.; Uchida, Y.; Berardi, V.; Calabria, N. F.; Catanesi, M. G.; Ospina, N.; Radicioni, E.; Langella, A.; De Rosa, G.; Collazuol, G.; Feltre, M.; Mattiazzi, M.; Ludovici, L.; Gonin, M.; Périssé, L.; Quilain, B.; Horiuchi, S.; Kawabata, A.; Kobayashi, M.; Liu, Y. M.; Nishimura, Y.; Okazaki, R.; Akutsu, R.; Friend, M.; Hasegawa, T.; Hino, Y.; Ishida, T.; Kobayashi, T.; Jakkapu, M.; Matsubara, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Yrey, A. Portocarrero; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Bhuiyan, N.; Burton, G. T.; Kralik, R.; Latham, N.; Di Lodovico, F.; Gao, J.; Katori, T.; Migenda, J.; Ramsden, R. M.; Xie, Z.; Zsoldos, S.; Ito, H.; Sone, T.; Suzuki, A. T.; Takagi, Y.; Takeuchi, Y.; Wada, S.; Zhong, H.; Feng, J.; Feng, L.; Han, S.; Hikida, J.; Hu, J. R.; Hu, Z.; Kawaue, M.; Kikawa, T.; Nakaya, T.; Ngoc, T. V.; Wendell, R. A.; Yasutome, K.; Jenkins, S. J.; Mccauley, N.; Tarrant, A.; Fanì, M.; Wilking, M. J.; Xie, Z.; Fukuda, Y.; Menjo, H.; Yoshioka, Y.; Lagoda, J.; Mandal, M.; Prabhu, Y. S.; Zalipska, J.; Mori, M.; Jia, M.; Jiang, J.; Shi, W.; Hamaguchi, K.; Ishino, H.; Koshio, Y.; Nakanishi, F.; Sakai, S.; Tada, T.; Tano, T.; Ishizuka, T.; Barr, G.; Barrow, D.; Cook, L.; Samani, S.; Wark, D.; Holin, A.; Nova, F.; Jung, S.; Yang, J. Y.; Yoo, J.; Fannon, J. E. P.; Kneale, L.; Malek, M.; Mcelwee, J. M.; Peacock, T.; Stowell, P.; Thiesse, M. D.; Thompson, L. F.; Wilson, S. T.; Okazawa, H.; Lakshmi, S. M.; Kwon, E.; Lee, M. W.; Seo, J. W.; Yu, I.; Ichikawa, A. K.; Nakamura, K. D.; Tairafune, S.; Eguchi, A.; Goto, S.; Hayasaki, H.; Kodama, S.; Masaki, Y.; Mizuno, Y.; Muro, T.; Nakagiri, K.; Nakajima, Y.; Taniuchi, N.; Watanabe, E.; Yokoyama, M.; De Perio, P.; Fujita, S.; Jesús-Valls, C.; Martens, K.; Marti, Ll.; Tsui, K. M.; Vagins, M. R.; Xia, J.; Izumiyama, S.; Kuze, M.; Matsumoto, R.; Terada, K.; Asaka, R.; Ishitsuka, M.; Shinoki, M.; Sugo, M.; Wako, M.; Yamauchi, K.; Yoshida, T.; Nakano, Y.; Cormier, F.; Gaur, R.; Gousy-Leblanc, V.; Hartz, M.; Konaka, A.; Li, X.; Smithers, B. R.; Chen, S.; Wu, Y.; Xu, B. D.; Zhang, A. Q.; Zhang, B.; Girgus, M.; Govindaraj, P.; Posiadala-Zezula, M.; Prabhu, Y. S.; Boyd, S. B.; Edwards, R.; Hadley, D.; Nicholson, M.; O'Flaherty, M.; Richards, B.; Ali, A.; Jamieson, B.; Amanai, S.; Bronner, C.; Horiguchi, D.; Minamino, A.; Sasaki, Y.; Shibayama, R.; Shimamura, R.; Null, Null. - In: PHYSICAL REVIEW C. - ISSN 2469-9985. - ELETTRONICO. - 112:6(2026). [10.1103/b93l-dbpj]
Measurement of the branching ratio of 16N, 15C, 12B, and 13B isotopes through the nuclear muon capture reaction in the Super-Kamiokande detector
Berardi, V.Membro del Collaboration Group
;Calabria, N. F.Membro del Collaboration Group
;
2026
Abstract
The Super-Kamiokande detector has measured solar neutrinos for more than 25 years. The sensitivity for solar neutrino measurement is limited by the uncertainties of energy scale and background modeling. Decays of unstable isotopes with relatively long half-lives through nuclear muon capture, such as 16N, 15C, 12B, and 13B, are detected as background events for solar neutrino observations. In this study, we developed a method to form a pair of stopping muon and decay candidate events and evaluated the production rates of such unstable isotopes. We then measured their branching ratios considering both their production rates and the estimated number of nuclear muon capture processes as Br(16N) = (9.0 ± 0.1)%, Br(15C) = (0.6 ± 0.1)%, Br(12B) = (0.98 ± 0.18)%, Br(13B) = (0.14 ± 0.12)%, respectively. The result for 16N has world-leading precision at present and the results for 15C, 12B, and 13B are the first branching ratio measurements for those isotopes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
